Systems and Methods for Sterilization

Abstract

Systems for sterilization of tissues, including acellular tissue matrices, comprising a package having a portion permeable to supercritical carbon dioxide and a portion impermeable to moisture are described. Methods of sterilizing acellular tissue matrices from soft tissues or demineralized bone are provided.

What is claimed is: 
     
         1 . A packaging system for a medical device, comprising an outer package, the outer package comprising a first portion and a second portion, wherein the first portion is permeable to supercritical carbon dioxide (SC—CO 2 ) and a sterilant and impermeable to bacteria, and wherein when the second portion is sealed it is impermeable to moisture;
 an inner structure configured to hold the second portion open during sterilization, wherein the inner structure is separate from the outer package; and 
 an inner package that is permeable to SC—CO 2  and a sterilant, wherein the inner package is positioned within the inner structure. 
 
     
     
         2 . The packaging system of  claim 1 , wherein the first portion comprises flash spun high-density polyethylene fibers. 
     
     
         3 . The packaging system of  claim 1 , wherein the first portion comprises medical grade paper. 
     
     
         4 . The packaging system of  claim 1 , wherein the second portion comprises foil. 
     
     
         5 . The packaging system of  claim 1 , wherein the inner package comprises flash spun high-density polyethylene fibers. 
     
     
         6 . The packaging system of  claim 1 , wherein the inner structure is permeable to supercritical carbon dioxide SC—CO 2  and the sterilant. 
     
     
         7 . A method of sterilization, comprising:
 selecting a medical device for sterilization;   placing the medical device in an inner package that is permeable to SC—CO 2  and a sterilant;   placing the inner package and the medical device inside an inner structure, wherein the inner structure is impermeable to SC—CO 2  and the sterilant;   placing the inner structure, the inner package, and the medical device in a first outer package, wherein the first outer package comprises a first portion that is permeable to SC—CO 2  and the sterilant and is impermeable to bacteria and a second portion that is impermeable to moisture when sealed; and   treating the medical device with SC—CO 2  and the sterilant, wherein the inner structure is configured to hold the second portion open during treatment.   
     
     
         8 . The method of  claim 7 , wherein the medical device comprises acellular tissue matrix. 
     
     
         9 . The method of  claim 7 , wherein the medical device comprises demineralized bone matrix. 
     
     
         10 . The method of  claim 7 , wherein the sterilant comprises peracetic acid (PAA). 
     
     
         11 . The method of  claim 10 , wherein the sterilant comprises a peroxide. 
     
     
         12 . The method of  claim 11 , wherein the peroxide is H 2 O 2 . 
     
     
         13 . The method of  claim 12 , wherein the concentrations of PAA and H 2 O 2  in the sterilant are 10-14% and 1-3%, respectively. 
     
     
         14 . The method of  claim 7 , wherein during the treating step, pressure and temperature are kept constant. 
     
     
         15 . The method of  claim 7 , further comprising sealing the second portion subsequent to sterilization. 
     
     
         16 . The method of  claim 7 , wherein the first portion comprises flash spun high density polyethylene. 
     
     
         17 . The method of  claim 7 , wherein the second portion comprises foil. 
     
     
         18 . The method of  claim 7 , wherein placing the inner structure inside the outer package maintains a flow path within the outer package during sterilization. 
     
     
         19 . The method of  claim 7 , wherein the structure maintains an opening within the second portion of the outer package during sterilization of the medical device. 
     
     
         20 . The method of  claim 7 , further comprising sealing the first portion prior to sterilization.